Billie Jean King has been awarded the Congressional Gold Medal, the United States Tennis Association said on Friday, becoming the first individual female athlete to receive the honor.

President Joe Biden signed the legislation into law on Thursday, recognizing King's groundbreaking contributions both on and off the court.

King has long been a trailblazer for gender equality in sports and society. The 80-year-old's relentless advocacy for equal pay in tennis led to the U.S. Open becoming the first Grand Slam tournament to offer men and women equal prize money in 1973, which cemented her legacy as a champion of women's rights.

An incredible honor for the remarkable Billie Jean King. pic.twitter.com/gCI3o43E7p

US Open Tennis (@usopen) September 27, 2024

That same year, King defeated Bobby Riggs in the 'Battle of the Sexes' match, a watershed moment for both tennis and the women's movement. Played in Houston's Astrodome, some 90 million tuned in worldwide to watch the match which further propelled the fight for equality in sports.

"Billie is one of the greatest athletes and ambassadors tennis has ever seen, but her impact off the court is even greater than her performance on it," said Brian Hainline, chairman and president of the USTA. "She has broken yet another barrier with this award."

King captured 39 Grand Slam titles in singles, doubles and mixed doubles. She was instrumental in founding the Women's Tennis Association.

King is among a select group of athletes to have received the Congressional Gold Medal. Eleven individual athletes, as well as the 1980 U.S. Olympic team, had received the Congressional Gold Medal, but before King all had been men.